1. Field of the Invention
The present invention relates to an engine component, e.g., a cylinder block or a piston, and a method for producing the same. More particularly, the present invention relates to an engine component composed of an aluminum alloy which includes silicon, and a method for producing the same. The present invention also relates to an engine and an automotive vehicle incorporating such an engine component.
2. Description of the Related Art
In recent years, in an attempt to reduce the weight of engines, there has been a trend to use an aluminum alloy for cylinder blocks. Since a cylinder block is required to have a high strength and high abrasion resistance, aluminum alloys which contain a large amount of silicon are expected to be promising aluminum alloys for cylinder blocks.
In general, an aluminum alloy which contains a large amount of silicon is difficult to cast, thus making die casting-based mass production difficult. Accordingly, the inventors of the present invention have proposed a high-pressure die casting technique which enables mass production of cylinder blocks using such aluminum alloys (see the pamphlet of WO 2004/002658). This technique makes it possible to mass produce cylinder blocks which have sufficient abrasion resistance and strength for practical use.
However, depending on the conceivable engine revolution and the conceivable conditions under which an engine may be used, a cylinder block may meet with even higher abrasion resistance and strength requirements. For example, in the case of a motorcycle, its engine is operated at a revolution of 7,000 rpm or more, so that there exist fairly high abrasion resistance and strength requirements for the cylinder block.